It is a common procedure to mount shanks of earth working tools to tool bars of agricultural equipment. The shank can be fixedly secured to the tool bar however it is desirable that the vertical height of the shank and thus the tool carried by the shank be conveniently adjustable. It is also desirable that the mounting arrangement for the shank firmly holds the shank in place when operating the shank and coupled tool in the ground.
A common system for mounting shanks to tool bars is to provide a series of holes in the shank, with cheek plates provided on opposite sides of the shank and mounted to the tool bar and bolts which are passed through the cheek plates and a selected hole or holes in the shank to set the height of the shank and clamp the shank in position. Vertical adjustment of the shank in such an arrangement is time consuming as the bolts have to be removed to allow the shank to be adjusted in height and then reinserted in a further hole or holes and through the shank. Further, the formation of such holes in the shank generally reduces the strength of the shank.
In another system, serrated tracks are provided in the rear of the shank which is again clamped between two cheek plates. Bolts which clamp the plates together also cooperate with the track for positive height location of the shank. This arrangement is also time consuming to adjust and height of the shank in this system is limited by the spacing of the serrations. Thus only “course” adjustment of the shank is possible.
In yet a further arrangement, the tool shank is held in position by a set screw which when tightened engages with the shank with a point contact. Whilst this arrangement can allow finer adjustment of the position of the shank, the arrangement is not particular secure with the result that when subject to load, the tool shank can often move or become dislodged from its set position.
In many situations for example where shallow cultivation is require, it is desirable to be able to accurately adjust the position or height of an earth working tool in the soil whilst at the same time ensuring that the tool does not move away from its set position however the currently known adjustment arrangements for a tool shank to which at tool may be mounted do not fulfil this requirement. It would be desirable therefore if a tool mounting assembly was available which addressed one or more of the above disadvantages.